Two men poisoned by carbon monoxide at Texas Motor Speedway

FORT WORTH, Texas -- Authorities said two men were rushed to hospitals in critical condition after being found suffering from carbon monoxide poisoning inside their converted bus at Texas Motor Speedway.

Fort Worth fire spokesman Kyle Clay said that firefighters found the men shortly before 9 a.m. Sunday. Bystanders had reported the men were ill inside the bus parked in the raceway's infield. A bystander was giving one of the men CPR when firefighters arrived.

Clay said that a gas-powered generator inside the vehicle wasn't properly ventilated. NASCAR's Texas 500 was running at the speedway Sunday.

Clay said that both men, who appeared to be in their 50s, were taken to the infield care center. One was airlifted to a hospital for treatment in a hyperbaric chamber. Their identities haven't been released.